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Detection Technology

Judge the failure of DC high voltage generator

time:2021/1/21   source:华天电力  reading:592 time

The DC high voltage generator provides a DC high voltage source, which is specially used to detect the electrical insulation strength and leakage current of power devices. It has a variety of protection functions, such as low voltage overcurrent, low voltage overvoltage, high voltage overcurrent, high voltage overvoltage, and zero protection , Non-grounding protection, etc., the fault sampling adopts a dedicated sensor, the action time is nanoseconds, and the optical isolation element is also nanoseconds. The action time is generally 10 microseconds to completely shut off the DC main circuit, thereby protecting the instrument to the greatest extent Not damaged.

Description of fault judgment of DC high voltage generator:

1. Connect the ground terminal on the control box panel and the ground terminal of the high-voltage tower with a ground wire and connect it firmly to the ground wire of the site or laboratory. To ensure the safety of you and the equipment, please check the ground wire repeatedly. Ensure that all parts are well grounded.

Use the provided seven-core cable to connect the control box and the high-voltage tower. Both ends of the cable are the same quick plugs. Pay attention to inserting the side gap of the plug to the thick convex part of the socket and tighten it clockwise. Connect the power cord. The power supply is single power frequency. AC 220V.

2. Turn on the power switch, the power switch light (green) and the panel meter are on at this time, and the high voltage switch is turned on, the high voltage indicator (green) is on, if the high voltage buzzer is in the on position, it will beep to prompt the operation When the high voltage is being applied, at this time, turn the high voltage output adjustment knob clockwise to increase the voltage. The voltmeter displays the KV value of the voltage on the test sample, and the ammeter displays the sum of the current flowing on the sample and all leakage currents. Including the current of the built-in high voltage divider, the current is microampere value.

DC Hipot Tester.png

If the power switch is turned on and the high-voltage switch is turned on, the high-voltage indicator light (green) does not light up, and the "return to zero" light (red) in the fault display is on, it means that the high-voltage output adjustment button is not at the zero position. Please turn the counterclockwise to The "return to zero" light is off, and then adjust clockwise to increase the voltage.

3. If the DC high voltage generator does not require voltage regulation protection within the rated output voltage range, turn the overvoltage protection setting button clockwise to the maximum value. At this time, when the output voltage exceeds the rated output voltage, it will automatically protect. Cut off the high voltage, if the voltage regulation protection is required within the rated output voltage range, please boost the no-load boost to the predetermined protection voltage according to the above steps, and then slowly turn the overvoltage protection setting knob counterclockwise to the required value On the voltage, perform the overvoltage protection action, the "overvoltage" indicator light is on, keep the overvoltage protection setting knob at this position, return the boost knob to the zero position, turn off the power, connect the test product, then the boost will exceed The high voltage is cut off when the predetermined voltage is reached.

4. When an overvoltage, overcurrent and other fault occurs, the high voltage is automatically cut off, the high voltage indicator light (green) is off, the buzzer stops beeping, and the corresponding fault indicator light is on, indicating that the product has been short-circuited. If you want to restart, you should The high voltage output adjustment knob returns to the zero position, the fine adjustment knob is also at the zero position, and then turn off the power switch, and then turn on the power switch to cut off the protection and re-boost.

(1) When shutting down during normal operation, first turn the high-voltage adjustment knob back to the zero position counterclockwise, then return the fine adjustment knob to the zero position, and finally turn off the power switch.

(2) The power switch is also used to protect the reset switch. When the fault indicator light (except the zero return indicator light) is on, the power switch should be turned off and on again to release the protection and re-boost.

5. When the DC high voltage generator load is a large capacitive load, in order to avoid overcurrent protection triggered by excessive charging current, please slow down the boost speed appropriately. After the test is completed, turn the output voltage adjustment knob counterclockwise to zero. Turn off the high-voltage switch. At this time, the voltmeter still displays the voltage value on the test product. Please wait for the test product to discharge below 20KV through the high-voltage tower before discharging with a ground rod to ensure safety.

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